Grounding connection

[tulum]

Does anyone know why a switchroom ground bus is on standoff insulators?

My guess is so if you want to test each ground connection (impedance) you can disconnect each one including the building and then reconnect one at a time a troubleshoot for the problem connection?

Regards,
TULUM

 

[weh3]

It's to make sure that the only path to the literal ground is through the grounding electrode conductor by way of the main bonding jumper.

William

 

[tulum]

Thanks weh3,

That was my first thought, but the bus is bonded to the building in 2 places, and all grounds coming off this insulated bus go to cubicle/switchgear grounds that are also bonded to the building.

Am I missing something?

 

[weh3]

Then the reason could be a simple practical matter of allowing you to get behind it to make connections.

William

 

[tulum]

THanks again.

That was actually my second thought. But another switchroom I was working in had this "ring" bus completely surrounding the interior of the building and on standoff insulators. That seems like a great extent to go to just for easier connections...

THe only thing I can think of is if they are having grounding issues they can remove each cable off the ground one at a time, until nothing is left but the ground grid... and sort things out from there...

Just a guess.

Thanks again,
TULUM